Tutorial: GameCenter Leaderboards in 5 minutes! (for intermediate/advanced scripters)

This is assuming you already have your GameCenter activated for your game at developer.apple.com, and never did this, or first time trying out Unity's Social API and could use a quick 5 minute explanation of how to get this thing working. As of this writing, Unity's Social API code is incomplete and every user will have to do additional searching to find out how to get the callback working. I'll have it explained out here for you guys instead.

1) From Unity's...

Tutorial: GameCenter Leaderboards in 5 minutes! (for intermediate/advanced scripters)